The Manson D38 (GNSR Class Q) 4-4-0 Locomotives

Manson's Class O (LNER D42) express
locomotives of 1888 were proving successful, so it was natural that when the Great North of Scotland Railway (GNSR)
required further express locomotives in August 1889, that the same basic design would be used.
The new locomotives were fitted with a new, larger eight wheel tender. Six locomotives were ordered and all were
delivered in 1890. Three kept the D42's 6ft 0.5in driving wheels and became
GNSR Class P (LNER D43). The remaining three had larger 6ft 6.5in driving wheels and
became GNSR Class Q (LNER D38). The D38s were Manson's last
locomotives for the GNSR, and were actually delivered after his resignation in August 1890.

The new eight wheel tenders fitted to the D38s were fitted with a leading bogie and two rigid rear axles.
At the time, these were the largest tenders in use on the GNSR and were designed specifically for
through workings between Aberdeen and Elgin. Their 4 ton coal capacity was exceeded by some later GNSR tenders,
but their
3000 gallon water capacity was never exceeded. Nos. 75 & 77 had later
Johnson-designed six wheel tenders fitted before
Grouping (1923). The LNER fitted a similar tender to No. 76 shortly after Grouping. All of the eight wheel
tenders were scrapped.

The GNSR "rebuilt" (ie. reboilered) all three locomotives. No. 77 was fitted with a superheated boiler with
a Schmidt superheater in August 1912. A superheated boiler was also fitted to No. 75 in July 1917, although the
superheater was of the Robinson type. No. 76 received a
replacement saturated boiler in May 1914. All three new boilers were of the same size and proportions as the original
boiler design. All were interchangeable with the boilers used on the
D42 and D43 classes; and very similar to the boilers used on the
D40, D41, and
G10 0-4-4T classes.
The LNER fitted new boilers to Nos. 75 & 76 (LNER Nos. 6875 & 6876), but No. 77 (LNER Nos. 6877) retained its
Schmidt boiler until withdrawal. No. 76 remained saturated until withdrawal.

The boilers were fitted with Ramsbottom safety valves. These were initially mounted with their
tall columns and spring exposed, but they were enclosed with neat casings when the new boilers were fitted.
Ross pop safety valves were later fitted by the LNER.

The GNSR usually allocated the D38s to Kittybrewster. Initially they were used on express trains between
Aberdeen and Elgin - a duty for which their large tenders were specifically designed for. They were also used to
haul passenger traffic on the Buchan line.

Immediately after Grouping (1923), No. 6875 continued to be allocated to Kittybrewster and worked the Deeside line.
No. 6876 was allocated to Keith, and No. 6877 to Elgin. Both hauled regular main line passenger services to Aberdeen,
and eventually returned to Kittybrewster.
As the only saturated D38, No. 6876 was also the first to be withdrawn (February 1931).
The remaining two D38s were often used on the passenger service between Banchory and Ballater. No. 6875 acquired
a particularly good reputation with the enginemen during this period, and was a favourite for excursion traffic.
The last two D38s were withdrawn in September 1937 (No. 6877) and January 1938 (No. 6875).

Technical Details

Saturated

Superheated

Cylinders (x2):

(inside)

18x26in.

18x26in.

Motion:

Stephenson

Stephenson

Valves:

slide

slide

Boiler:

Max. Diameter:

4ft 6in

4ft 6in

Boiler:

Pressure:

165psi

160psi

Diagram No.:

88

88

Heating Surface:

Total:

1165 sq.ft.

1000 sq.ft.

Firebox:

106 sq.ft.

106 sq.ft.

Superheater:

140 sq.ft. (18x1.1in)

Tubes:

1059 sq.ft. (213x 1.75in)

512 sq.ft. (104x 1.75in)

Flues:

242 sq.ft. (18x 4.75in)

Grate Area:

18.2 sq.ft.

18.2 sq.ft.

Wheels:

Leading:

3ft 9.5in

3ft 9.5in

Coupled:

6ft 6.5in

6ft 6.5in

Tender:

4ft 1in

4ft 1in

Tractive Effort:

(@ 85% boiler pressure)

15,050 lb

14,594 lb

Wheelbase:

Total:

43ft 3in

43ft 3in

Engine:

21ft 8in

21ft 8in

Tender:

13ft 0in

13ft 0in

Weight (full):

Total:

83 tons 8cwt

84 tons 8cwt

Engine:

46 tons 0cwt

47 tons 0cwt

Tender:

37 tons 8cwt

37 tons 8cwt

Adhesive Weight:

31 tons 15cwt

32 tons 5cwt

Max. Axle Load:

16 tons 10cwt

16 tons 13cwt

Preservation

The last D38 was withdrawn in 1938, and none have survived into preservation.